[Zefer]

Hello,
I am currently working on some code (class based) and I am wondering how I could make one class have a default - and permanent connection to a MySQL database.
Some pseudo-code of how I wish for this to work would be;

PHP Code:

class hooks {

 public function fetch_code ($hook_id) {

  return $this->ms_query("blah blah blah");

 };

}; 

But I would not like to have to write ms_query in that class itself. Any ideas?
Thanks in advanced,
Ryan

[wirehopper]

Create a database wrapper, so you call db->query() - which actually performs the mysql_query call.

You may be able to find some existing ones.

[carters-site]

DB
This is one I have used for a long time.

A lot of times on shared servers it already packaged with PHP. I know there is also MDB2 on the PEAR site that you can use also.

I would take the PEAR DB class and wrap it one more level if you want to maintain a constant DB connection (or at least reconnect on DB Host gone away)

Here is one I ripped from a project I did a few years back. It requires PEAR.php and Pear DB.
There is a little extra overhead in doing queries just to establish the connection. this is because I found mysql_ping unreliable at truly determining a MySQL connection resource is valid. Many time mysql_ping will return true but an actual query will result in "DB Server has gone away".

PHP Code:

class qcDB
{
    /**
    * connect
    * This will establish a connection to that database or check if there is an existing 
    * connection. 
    * 
    * @static
    * @return PEAR DB object $oDB 
    */
    static public function connect()
    {
        /* @static $oDB DB Object - connection to database using PEAR DB. */
       static $oDB = null;

      // Test the connection to make sure it truly is valid. 
      $xResult = $oDB->query("SELECT 1");
      if(PEAR::isError($xResult)){
         $oDB = null;
      }    
    
       if(is_null($oDB)){
          // Since this method is static connect to the Config Object manually
           $oConfig = new qcConfig();    
   
           // get the database options
           $kDBInfo = $oConfig->get('database'); 
   
           // map over values to their DSN values.
           $kDSN = array(
               'phptype' => 'mysql',
               'username' => $kDBInfo['user'],
               'password' => $kDBInfo['password'],
               'hostspec' => $kDBInfo['host'],
               'database' => $kDBInfo['database']
           );
   
           $oDB = DB::connect($kDSN);
         $oDB->setFetchMode(DB_FETCHMODE_ASSOC);            
      }
        return $oDB;
    }
    
    public function query($sSQL, $aVars = array()){
      $oDB = qcDB::connect();
      return $oDB->query($sSQL, $aVars);  
   }
} 

[Zefer]

Thanks for the replies but I think you guys missed the point of my question.
I want one MySQL class off which all my other classes, which too require a DB connection inherit it's values from.

[wirehopper]

Okay - then identify the common properties and methods and create them in the base class, all other classes will extend it.

I think you may find a good example in Zend Framework's database class, or perhaps any other framework.

If the properties are stored in the base class as an array, assignment, overriding and dynamic construction of the SQL is possible.